Fluid operated motor for deep well pumping equipment



March 17, 1942. G. KENNEDY ET A L 2,276,783

FLUID OPERATED MOTOR FOR DEEP WELL PUMPING EQUIPMENT 2 Sheets-Sheet '1Filed Nov. 7, 1938 ISnuentors:

March 17, 1942.

G'. KENNEDY ETAL Filed Nov. 7, 1938 2 Sheets-Sheet 2 II I l/v////V///////////////// lllllllllll 3 4 M 0 -10, f a% 1, c 5

5 4 0 7 /47 T W 9 /2 0 0 7 9 8 8 7 9 0 9 3 x 32 4 2 3 2 W Patented Mar.17, 1942 FLUID OPERATED MOTOR FOR DEEP WELL PUMPING EQUIPMENT.

Glen Kennedy and C. 0. Cole, Whittier, Calif. Application November 7,1938, Serial No. 239,258 Q 6 Claims.

This invention relates in general to fluid motors and in particular to afluid motor adapted to be positioned in a well bore for operating a deepwell pump which may be associated with it. The pump preferably being ofthe double acting type.

While this motor may be applied to pumps used for many purposes, it isparticularly adaptedto the operation of deep oil well pumps. Whenutilized for this purpose, the motor, having the pump associated withit, is suspended from the lower end of a string of production tubingextending downwardly in the well bore. A string of pressure tubing,preferably disposed inside the production tubing, conducts a motivefluid from a surface pressure pump to the motor. The production tubingserving to conduct to the surface the discharge of the pump and theexhaust fluid from the motor.

It is an object of this invention to provide a fluid operated motor of ahighly simplified design which consequently may be easily andeconomically manufactured and is comparatively free from mechanicalbreakdown in operation.

It is a further object of this invention to produce a fluid motor havingbut two moving parts, a piston and a control valve, which is positive inoperation and which cannot get on dead center.

It is still another object of this invention to provide a fluid motor inwhich the two moving parts, a piston and a control valve, are bothdisposed in the piston chamber whereby the wearing surface is materiallyreduced under that of motors of a similar character which requireseparate chambers to receive the valves.

The essence of this invention which renders the foregoing and otherobjects possible of accomplishment resides in the concepts and in themethods of closing off the supply of fluid from the supply port to thepiston chamber while the valve is being shifted by the fluid underpressure; of discharging fluid from the valve space; of starting thepiston in the reverse direction as the valve completes its movementrelative to the piston; in carrying the valve by the piston, and in thecooperative relationships which exist between the various elements ofthe mechanism and their respective fluid passages as follows:

1. Between fluid passages provided by the chamber wall and fluidpassages provided'by the piston.

2. Between fluid passages provided by the chamber wall and,respectively, the valveand valve fluid passages.

'3. Between the piston fluid passages and, respectively, the valve andvalve fluid passages.

Other objects and advantages of this invention will be made apparent inthe description which follows and in the accompanying drawings.

In these drawings:

Fig. 1 is a diagrammatic view showing the motor of this inventionattached to a pump.

Fig. 2 is a vertical sectional View of the motor of this invention,showing the valve in #1 control position. v

Fig. 3 is similar to Fig. 2, except that the valve is shown in its otheror #2 control position.

Fig. 4 is a horizontal sectional view taken on the line CCC of Figs. 2and 3.

Referring to Fig. 1, a method of connecting the motor of this inventionto a pump is shown. A string of pressure tubing communicating with asource of operative fluid under pressure is threadably attached to theoutside shell 58 of the motor. Shell 38 providing a passage to the motorsupply port as will be explained later. Motor piston chamber threadablyengages. one end of head I, the opposite end of head 1 being threadablyreceived by one end of connecting sleeve 46. Head 41 serves as shown tothreadably connect sleeve 46 and pump &8 and to threadably receive thelower end of a string of production tubing 53.

Motor piston rod 10 and pump rod 52 are connected by rod connector 50.Rod connector 50 provides opening 32 in communication with motorexhaust, as will be explained later, and with the discharge from thepump. Pump rod 52 is provided with a passage adapted to receive pumptive fluid and methods of installation and operation in the well bore offluid operated motor' pumps are matter which have been described in thepatent literature and are well understood by oil field workers. Theywill, therefore, not be made subjects for discussion here.

Referring to Fig. 2, a preferred construction of the motor is shown indetail. A cylindrical piston chamber 5 is closed at one end with a head6 and is provided at the other end with a head I .which provides a gland8 and a stuffing box 9 the valve being retained in place on the pistonby heads I3a and I3b, head |3,a being threadably attached to the piston,as shown. It will be observed that heads I4 and I 5 provided by thevalve and piston heads I3 and I4 are in slidable and substantiallyfluid-tight contact with the inside chamber wall.

The piston, as shown, has formed therein a longitudinal primary passageI6, having primary, secondary, and tertiary and quaternary openings,designated as IT, I8, I9 and 20, respectively; and also a longitudinalsecondary passage 2| having primary, secondary, tertiary and quaternaryopenings designated as 22, 23, 24 and 25 respectively; passage I6connecting with the upper, and passage 2| connecting with the lower endof chamber 5. The piston further provides a longitudinal passage 26connecting with a transverse passage 21 and passage 28 connecting withexhaust by opening 32, formed. in piston rod I0. Since passages 21, 26,28 and opening 32 constitute a passage leading to exhaust, hereinafter aconnection to passage 2'! will be termed as a connection to exhaust.

Valve I2 provides primary and tertiary openings 33 and 3| connectingrespectively with annular channels 29 and 34 and furthermore provides asecondary passage in the form of an annular channel in connection at alltimes with transverse passage 21. Channel 30 being wide enough to coverpassage 21 with sleeve valve I2 in either one of its extreme positions.

The piston chamber 5 has formed in its inside wall primary and secondarychannels 36 and 31 and a supply port 35, channels 36 and 31 beingaxially equidistant from supply port 35. A shell attached to the chamberat 39 provides a channel for conducting motive fluid to the chambersupply port 35.

It will be observed that piston heads I3a and I3!) serve to limit thetravel of valve I2, the distance of travel being that required to bringinto proper registration the various cooperating ports and openings, aswill be explained later.

It is also desired to point out that valve heads I4 and I5 in slidablecontact with the inner surface of chamber 5 serve to define an annularpassage 40.

With valve I2 in the position relative to the piston, as shown in Fig.2, but with the piston slightly lower down in the chamber than shown, itwill be apparent that a passage is established leading from supply portthrough annular passage 4|), through valve opening 33 and piston opening24 into piston passage 2| and thence to the lower end of piston chamber5. With shell 38 connected to a source of operative fluid under pressurefluid will flow through annular passage 42 to supply port 35 and thencethrough the passage as above described to the lower end of chamber 5where it will act to force the piston in the upward direction. It shouldbe noted that space 4| between valve head I4 and piston head |3a isconnected with piston passage 2| by opening 23, consequently space 4| isfilled with operative fluid under pressure whereby valve I2 iseffectively held in its control position.

With the valve in the control position with respect to the piston, asabove described, it will be clearly seen by referring to Fig. 2 that apassage for the exhaust of fluid from the upper end of chamber 5 isprovided through piston passage I6 and opening 20 into sleeve valvepassage 30 which connects to xhaust.

With piston I I and valve I2 in the positions shown in Fig. 2 it will beapparent that'valve head I5 has shut off the connection between supplyport 35 and annular passage 40. Obviously, in this position no fluid canflow from supply port 35 to piston chamber 5; however, the full pressureof the operative fluid is applied against valve head I5 to move it inthe upward direction.

As shown in Fig. 2, chamber annular passage 36 connects space 4| andpiston opening 22 with piston in this position. Operative fluid pressureacting against valve head I5 causes the valve to move upwardly forcingfluid from space 4| through annular passage 36 and opening 22 thencethrough piston passage 2| into the lower end of chamber 5 closed offfrom exhaust at this time whereby the piston is caused to move upwardly,the upper end of chamber being open to exhaust. This movement of thepiston continues until the valve has moved to the point where valveannular passage 30 connects opening 25' with exhaust passage 21 wherebya passage is set up from space 4| through annular passage 36, pistonopening 22 and passage 2| to opening 25 then through valve annularpassage 30, and, as already described, thence to exhaust.

It should be pointed out in a general way that in fluid motors of thischaracter open exhaust passages must be maintained at all times as wellas supply passages if the various fluid operated parts are to continuein motion and the motor is not to stall. It is therefore necessary toprovide a slight overlapping of openings 20 and 25.

It will be seen that valve I2 in the course of its movement from controlposition #1 as shown in Fig. 2 to control position #2, as shown in Fig.3 first closes opening 20 thus closing the passage established for theexhaust of fluid from the upper end of chamber 5 and just before opening20 is completely closed valve passage 36 slightly laps opening 25 forreasons already stated. At this point openings 23 and 33 are closed,opening 3| is slightly lapping opening I9 and not until valve I2 hassubstantially completed its movement is opening I8 which is made narrowfor this purpose connected to supply port 35. Opening I8 is a startingport and provides in part a passage for the flow of fluid to start thepiston in the reverse direction as will be explained later. It thusbecomes apparent that the piston moves the valve into operative relationwith supply port 35 and passage 36, that at this point the supply ofoperative fluid is closed off from the piston chamber by valve head I5and therefore the valve is maintained in operative relation with supplyport 35 and passage 36 until it has completed its movement. Obviously itis impossible for the piston or valve to get on a dead center. It willbe noted that the movement of the piston due to valve movement in eitherdirection is very slight, due to the fact that fluid is forced againstthe piston head during only of the total movement of the valve, duringthe last of valve movement a passage to exhaust is provided,furthermore, the effective area of a valve head is much less than theworking area of a piston head and the total movement of the valverelative to the piston is small.

Referring now to Fig. 3 it will be noted that valve I2 is in controlposition #2, that is, it is in its extreme upward position and passageshave been established for the exhaust of fluid from the lower end ofchamber 5 and for the supply of fluid to the upper end of chamber 5 toeffect the downward movement of piston I.

In the position of piston I I and valve I2 shown in Fig. 3 it isapparent that a passage for the supply. of fluid has been establishedfrom supply port 35, through opening l8 and thence through pistonpassage I to the upper end of chamber 5. As piston I l moves a slightdistance in the downward direction Valve. head l5 will connect supplyport 35 with annular passage 40; the passage for the supply of fluid tothe upper end of piston chamber 5 will then be from supply port'35,through annular passage 40, through openings 3| and l9 and thence alongpiston passage l6. It will be noted that supply port 35 is sufficientlywide to permit valve head I5 to pass it without being closed and thatfluid pressure is maintained in space 44 through opening l8, thusholding valve I2 in position.

As shown in Fig. 3 a passage for conducting fluid from the lower end ofchamber 5 to exhaust is set up as follows: through piston passage 2| toopening thence through valve passage 3!) to exhaust.

With valve [2 in the position relative to piston l l as above describedand shown in Fig. 3, the piston will travel downwardly until the fluidfilled space 44 is connected to piston passage opening I! by passage 31and valve head 43 closes 01f supply port 35 from the established passageleading to the upper end of chamber 5, the situation being entirelyanalogous to that shown in Fig. 2 and already described.

Fluid pressure acting against valve head l4 moves valve 12 downwardly.During the'flrst /2 of the valve movement fluid from space 44 is forcedthrough passage 31, and opening l1 along piston passage l6 and thenceinto the upper end of piston chamber 5 whereby the piston is moveddownwardly a slight distance, at this time the upper end of pistonchamber being closed off from exhaust and the lower end open thereto. AsValve l2 completes its movement, valve passage connects opening 20 toexhaust, whereby a passage from space 44 to exhaust is provided throughopening I 8 and along passage Hi to opening 20.

With the piston in its extreme downward position and with valve i2having completed its movement valve 12 is now in a position with respectto the piston, as shown in Fig. 2 and with a passage to exhaust setup aspreviously described. However, valve head [4 has supply port closed offfrom annular passage 40. Opening 23 being connected to supply port 35fluid flows through opening 23 and passage 2| to the lower end ofchamber 5 causing the piston to start moving in the upward direction. Asvalve head l4 passes supply port 35 a supply passage is set up as firstdescribed and the piston continues to move in the upward direction tothe position shown in Fig. 2. Thus the cycle is completed. Obviously,with a continuous supply of operative fluid the piston will continue toreciprocate.

It will be apparent that valve l2 in shifting from control position #2to control position #1 moves in a manner analogous to the shift fromposition #1 to position #2. In the course of the first part of valvemovement from position #2 to position #1 openings 25, I9 and I8 areclosed. As the valve continues its movement, opening 20 is connected toexhaust by passage 30, there being, as previously explained, a slightoverlapping of openings 23 and 25, passage 30 being sulficiently wide toeffect this; opening 24 registers with opening 33 and just before valvemovement is completed opening 23 is connected to supply port 35. Asexplained with regard to opening l8, opening 23 is made narrow to insurethat before it is connected to supply port 35 valve movement will besubstantially completed.

. Since openings I8 and 23 act as starting ports, there is therefore nopossibility 'of the piston starting in the reverse direction from eitherone of its extreme positions before valve movement is completed.

It should be noted that although for the sake of clarity asomewhat'lengthy and detailed description of valve action has been givenvalve movement is actually relatively rapid. The rapidity of action, ofcourse, being dependent on the rate at which motive fluid is supplied tothe motor.

Thus it will beseen that a motor, operative by oil as the motive fluid,has been produced, the valve action of which is rendered positive at-alltimes by the foregoing described arrangement of passages and ports.Byfirst connecting the space ahead of the valve to a piston chamber endclosed off from exhaust and subsequently, in consequence of valvemovement, providing a connection to exhaust provision is made for thecomplete exhaust of fluid trapped ahead of the valve and the maintenanceof live fluid pressure against the other end of valve throughout itsentire course of travel without possibility of a connection betweensupply and exhaust occurring at any time. Obviously in a motor operatedby an incompres- 'sib1e fluid such as oil any fluid trapped ahead of thevalve would block its action.

We claim:

1. In a fluid operated motor: a motor body providing a chamber; a pistonslidable in said -cham'ber providing'a valve space, a valve insaidspace, a port opening through one end of said piston, another portopening through the opposite end of said piston, one of said portscoopcrating with a suitable passage provided by the chamber at neextreme limit of piston travel'and the other of said portscooperatingwith another chamber passage at the opposite extreme limit ofpiston travel to set up a passage in each case for the discharge offluid from said valve space into that end of said chamber closed offfrom exhaust at that time.

2. ma fluid operated motor the combination of "abody -providing achamber and passages;

a piston providing a valve space; a fluid operated valve slidablyassembled in said space; said piston providing primary and secondarylongitudin'al passages opening through and extending back from oppositeends of said piston, said passages each providing: a primary openingadapted to cooperate with one of said chamber passages to conduct fluidfrom said valve space to end of said chamber closed off from exhaustduring first part of valve shift, a secondary opening, valve controlledand arranged to open as said valve reaches an extreme limit oftravel,tertiary and quaternary openings arranged to cooperate with passagemeans provided by said valve to control the supply and exhaust of fluidto and from said chamber.

3. In a fluid operated motor the combination of: a motor body providinga chamber and passages; a piston comprising two heads anda connectingbody portion of reduced diameter thereby providing a valve space; asleeve-like valve providing supply ports and an exhaust passage slidablyassembled on said body portion between said two heads; said pistonproviding primary and secondary longitudinal passages opening throughand extending back from opposite ends of said piston, said passages eachhaving lateral openings as follows: a primary opening through a pistonhead opposite to that end of the piston from which its respectivepassage extends, said opening being adapted to cooperate with a chamberpassage to conduct fluid from said valve space, a secondary openingthrough said piston body, valve controlled and arranged to open as saidvalve reaches an extreme limit of travel, a tertiary opening throughsaid piston body adapted to cooperate with one of two supply portsprovided by said valve and a quaternary opening controlled by an exhaustpassage formed in said valve in communication wit-h exhaust at alltimes, said piston providing a passage leading to exhaust having alateral opening through said piston body covered by said valve exhaustpassage at all times.

4. In a fluid operated motor: a motor body providing a chamber andpassages in the wall thereof and intermediate said passages a supplyport; apiston in said chamber providing a valve space and a longitudinalpasage opening through the first end of said piston and laterallythrough said piston adjacent its second end, another similar passageopening through said piston second end and laterally through said pistonadjacent its first end; a fluid operated valve slidable in said valvespace and providing means to control the supply of fluid from saidsupply port; one or the other of said chamber passages being adapted assaid piston approaches one or the other of its extreme limits of travelto connect one end of said valve space with the piston passage lateralopening in communication with the end of said chamber closed off fromexhaust at that time at substantially the same time that said fluidsupply port registers with the other end of said valve space and controlmeans provided by said valve close off the communication between saidsupply port and said chamber whereby the shifting of said valve ispermitted and effected.

5. In a fluid operated motor the combination of: a motor body providinga chamber and in its side fluid passage means adjacent each end andintermediate thereof a supply port; a piston comprising two heads and aconnecting .body portion of reduced diameter thereby providing a valvespace; a sleeve-like valve providing supply ports and exhaust passageslidably assembled on said body portion between said two heads; saidpiston providing primary and secondary longitudinal passages openingthrough and extending back from opposite ends of said piston,

.exhaust;

said passages each having lateral openings as follows: a primary openingthrough a piston head opposite to that end of the piston from which itsrespective passage extends, said opening being adapted to cooperate witha chamber passage to conduct fluid from said valve space at extremelimits of piston travel, a secondary opening through said piston body,valve controlled and arranged to open as said valve reaches an extremelimit of travel, a tertiary opening through said piston body adapted tocooperate with a valve fluid supply port and a quaternary openingcontrolled by said valve exhaust passage; said piston providing apassage leading to exhaust having a lateral opening through said pistonbody covered bysaid valve exhaust passage at all times; said valveconstructed with a flange adjacent each end thereof and adapted tocooperate with said chamber fluid supply port to close off the supply offluid to said piston chamber ends during the time fluid is supplied to avalve space end to effect valve movement.

6. In a fluid operated motor the combination of: a motor body providinga chamber, a supply port and two passage means; a piston slidablymounted in said chamber, and providing a valve space; a valve in saidspace; said piston providing an exhaust passage and fluid passage :meansin alternate valve controlled communication with said exhaust passagefor conveying fluid to and from opposite ends of said chamber to actuatesaid piston comprising a longitudinal passage opening through andextending from the end of the first piston head to and opening laterallythrough the second piston head and another longitudinal passage openingthrough and. extending from the end of the second piston head to andopening laterally through the first piston head; as said pistonapproaches an extreme limit of travel, one of said body passages isadapted to provide a connection between the lateral opening incommunication with that end of chamber closed ofi from exhaust at thattime and one end of said valve space whereby initially,

a passage is established for the discharge of fluid from said valvespace end into said chamber end and subsequently in consequence of valvetravel a passage is provided leading to the complete shifting of saidvalve thereby being permitted and connection between supply and exhaustprevented.

GLEN KENNEDY.

C. C. COLE.

